im still not sure im gonna update.. *knocks on wood* I havnt had any problems with the version im running....
I think there are some security fixes, so yea, you might want to update. I'am hoping to get my forums updated this weekend.
Both 3.8.3 and 3.8.4 are bug fixes not security fixes. While it is in your best interest to upgrade, there is no urgency to do so. However there is a fairly large memory issue in vBulletin that was fixed in vBulletin 3.8.4. You can look in the Announcement on vBulletin.com to see the fix and backport that to 3.8.2 but upgrading should be minor.
Yes. According to this post: vBulletin Community Forum - View Single Post - vBulletin 3.8.4 Released All versions 3.6 and higher are affected.